Electrical distribution system



March 4, 1958 A. R. coNsTANTlNE ETAL 2,825,775

ELECTRICALDISTRIBUTIONSYSTEM Original Filed Nov. 3, `1954 3 Sheets-Sheet 1 s am 5 Sheets-Sheerl 2 A. R. CONSTANTINE ETAL ELECTRICAL DISTRIBUTION SYSTEM March 4, 1958 Original Filed Nov. 5, 1954 lli FM4 D March 4, 1958 A. R. coNsTANTlNE ET AL 2,825,775

ELECTRICAL DISTRIBUTION SYSTEM Original Filed Nov.. 3. 1954 Sheets-Sheet 3 INVENTQR.

:Unit @ISS ELECTRICAL DISTRIBUTION sYsrm/i Constantine, Longmeadow, Mass., and Elmer T. Carlson, Center Valley, Pa.

Original application November 3, 1954, Serial Filo. 466,466, now Patent No. 2,786,908, dated March 2d, 1957. Divided and this application January 1956, Serial No. 558,029

10 Claims. (Cl. 20th-5d) rThe invention relates to the class of electrical distribution systems sometimes referred to as the bus-duct type. Such systems generally comprise a-duct run containing bus bars and having associated therewith at desired intervals current takeoff devices, sometimes identified as plug-in devices.

present application is a division of our copending application Serial No. 466,466, tiled November 3, 1954, for Electrical Distribution System. The subject matter relating to the interlocked switch and cover combination has been retained in the parent application.

ln prior art duct run constructions, the duct run generally includes a metal casing through which the bus bars pass. The casing is usually apertured at various points therealong so as to permit the contacts of a plug-in device to be inserted through the casing and into engagement with the bus bars therewithin.

rThis invention contemplates a take-off device which provides marked improvement in the electrical circuit efficiency. lt oifers safety from electrical shock and burns to operating personnel. Further, it conserves labor and materials in its manufacture.

This invention relates particularly to new and useful improvements in a plug-in or connector box having retractable contacts and an interlocked cover to prevent the opening of the box when the contacts are in the engaged position.

lt is further directed to connecting means between the connector box and the bus duct with which it is normally associated.

it is the principal object of the invention to provide a novel and improved plug-in device of the type in which the plunger contacts for connecting to the bus bars may be withdrawn into or extended from the plug-in enclosure by safe external means, and in which, the door or cover of the enclosure cannot be opened until the contact plungers are withdrawn away from the bus bars with which they are in contact when in the operative position.

A further feature of the invention is the provision of means whereby, when the cover of the plug-in device can be opened, the entire contents of the box are dead, or

free from current low.

A still further object of the invention is the provision of means for attaching plug-in devices to opposite sides of an insulator support, and to make the contact with the bus bars on opposite sides thereof by means of contactors passing through openings in the insulators and held under pressure against the bars.

Practically all of the commercial forms of the bus duct consist of an elongated housing, which has spaced intermittently along its length porcelain or other insulators, which support the bus bars. Something equivalent to a knife switch is introduced for each one of the conductors at a plug-in window or opening in order to make the desired connection. Ordinarily, the access opening is located in between the insulators.

The plug-in systems of prior art manufacture require that in eect a knife switch type of plug connector be fit1 2,825,775 Patented Mar. 4, 1958 ice 2 made in an open window at voltages of as much as 600 volts. This objection is complicated by the fact that the workman concerned therewith may be on top of a ladder or scaffold where the danger from falling is as great as the hazard from electrical shock. One of the main objectives of the present invention is to overcome this hazard and to make the device not only safe but also foolproof.

Due to the lack of standardization in prior art devices, there is a large inventory cost in almost all of the existing bus ducts. One of the prime purposes of the device of this invention is to overcome this objection.

Further, the existing equipment is expensive in respect to the materials employed. The present invention contemplates reducing the cost of the component parts, as well as reducing the diversity thereof.

The prior art bus way has access openings for plug-in purposes which can be opened by a workman at any time without regard to the position of his plug-in mechanism. The present device has eliminated such possibility. The workman here cannot open the bus duct window unless he has first applied his plug-in mechanism to a position which assures that the window is covered and is safe. The same would be true of any inspection or test equipment which might be attached to a test plug-in mechanism such as meters and the like.

The way in which this interlock or safety lock is accomplished is that the plug-in mechanism must depress pins which otherwise prevent the slider from operating. When the plug-in mechanism depresses the pins, the slider in the wall of the bus way is free to move.

Unlike all existing bus ducts, the idea of pinching or clipping on the conductor for contact has been given up. The new form of plug-in involves a high pressure Contact of the character of a circuit breaker contact rather than a knife switch. To assure that the condition will be favorable, each of the bus bars will be silver plated, and the contact will be silver coated.

ln accomplishing the arrangement of the plug-in, there are the following features to consider:

(a) As the operating handle outside of the box first swings, it brings the individual contactors into engagement with the bus bars.

(b) On further downward motion the toggle action is thrown beyond its toggle center to apply pressure to the bus bars.

(c) Coincidentally with the throwing of the toggle beyond its toggle dead center, there is the swinging of double break contact switches which close circuits.

(d) The door must be closed before you can operate this handle and the door lock is secured before even the first contact is made. In reversing to open, the toggle assures a quick break and coincidentally the double break switch opens the circuit, followed by the breaking of the contact engagement with the bus bar itself. The last thing that happens is the release of the door lock.

The important consideration is that the plug-in box can be a standard component and the interior electrically protective equipment can vary with the demand of the particular job. For example, it can be a fuse protective device, a circuit breaker mechanism, special test mechanism, or individual adapting mechanism such as transformer, wiring terminal board, or the like.

It will be evident also that the structure of the invention can be used for other than general distribution purposes such as, starting and control circuits, in which case the plug-in box might include the motor starter, the motor protective equipment, or the program control of a particular machine tool, or the special warning apparatus incident to the operation of a particular' tool. In other words, wherever a box of the conventional motor starter or control type is used, the plug-in box can be adapted.

These plug-in devices are equally adaptable to many 74 slidable up and down thereon.

assente other product classes such as, panelboards, switchboards, safety switches, motor control center, enclosed circuit breakers, motor control devices, drawout switchgear, and the like.

All of the above cited objects we accomplish by means of such structure and relative arrangement of parts thereof, as will fully appear by a perusal of the descrip tion below.

Fig. 1 is a plan view of the plug-in box of the invention with a portion of the -cover thereof removed;

Fig. 2 is a combined Side elevational and sectional view through the box shown in Fig. 1;

Fig. 3 is an end elevational view of the box shown in Fig. l;

Figs. 4 and 5 are side elevational views of insulators;

Fig. 6 is an elevational view of the fixed insulator with the stationary contactors associated therewith; and

Figs. 7, 8 and 9 are diagrammatic views showing various relationships of the stationary and movable eontactors with the switch bars associated therewith.

Referring now to the drawings more in detail, in which similar characters of reference indicate corresponding parts in the several figures and referring more particularly to the preferred form of our invention selected for illustrative purposes, we have shown a box 2 Iwhich has bottom, side and end walls d, 6 and A cover iti is suitably hinged to the box, as at l2, for swinging between the closed position shown and an open position indicated by dash lines in Fig. 3.

An insulator i4, a side elevational view of which is shown in Fig. 5, is secured by suitable means, such as screws 16, to the bottom wall 4 of the box 2. The

insulator has recesses i8 which are open at `upper sides thereof and a recess 2@ which is open at its lower side. See Fig. 5.

A stationary contacter 22 of suitable metal, more or less in the shape of a G, is provided and has an upper portion 2d, in a notch 2d of insulator 14. A lower part 26 of said connector extends forwardly, as shown in Fig. 2.

Other stationary contacter-s, such as 2S, have upper portions Sil in recesses 32 of insulator ifi and have lower portions 34 in the recesses i8 thereof.

rl`he connectors just described may be connected in circuits or portions thereof or to components in circuits. For illustrative purposes, clips such as 36 and upper portions of the contactors are secured to the insulator by such means as bolts 3S.

The clips 3o receive tangs 4t2 of fuse members e2 having tangs on opposite ends which are receivable in similar clips such as id secured to an insulator 45 that is secured in turn to the box. A lug 48 is secured to each clip 44 for connection to the wiring of a circuit.

Cables or wiring may be brought into the box through knock-out openings as is usual in electrical equipment.

A circuit breaker or breakers or other devices may be used in the box in lieu of the fuse member, if desired.

A carrier is provided which includes a transverse channel 50 having an insulator 52 secured therein in a suitable manner. The channel has opposite ends Se pivotally connected at 56 to the ends of parallel links SS which are pivoted at 6i? to the side walls 6 of the box. By means of the links the carrier is movable up and down to extend and retract contactors to be described.

The insulator SZ is provided with outwardly extending hubs 62 in which movable contactors 64 are reciprocable. The contactors are urged outwardly relative to the hubs by springs tid which act on washers or bearing rings 6d slidable in the hubs and held in the contactors by split rings 63 in grooves of the contactors or the like. Other split rings 7@ in grooves at the upper ends of the con* tactors limit outward movement thereof.

Guides 72 fixed in the insulator 52 have metallic blades Springs 76 between the blades and abutments 7S urge the blades downwardly. See Fig. 2.

Portions of the blades are adapted to engage the stationary and movable contactors and the engageable portions of these components are provided `with engageable buttons commonly employed in circuit opening and closing apparatus. The blades may be referred to as switch devices for connecting the stationary and movable contactors.

Operating mechanisms for extending and retracting the insulator 52, and thereby the contactors 64, are provided.

A lever S9 is fixed to a shaft $2 journalled in the end wall of the box and is pivotally connected to the channel of the carrier as by a link 84 pivoted at de and $8 to the lever and channel. See Fig. 3. A manually engageable member 90 is iixed to said shaft.

The parts are shown in the extended position of the contactors ed wherein the lever Sti abuts a stop 92. The parts are so arranged that the pivot 85 is slightly at one side of a line extending through the pivot 83 and the axis of shaft 82. This is so that the lever and link function with a toggle action whereby the parts are releasably lheld in extended positions of the contactors 64.

A rod 94 pivoted at 96 to the lever Sil has an end freely slidable in a bracket 98 and a spring itl@ acts to bias the lever Si? to the positions shown in Fig. 3.

By swinging member 9d clockwise the carrier is moved upwardly Iso that the contactors 64 are moved upwardly or are reciprocated from extended position. During this movement of the carrier, the blades 74 are moved out of ycontact with portions 26, 34, of the stationary contactors for circuit opening purposes. Clockwise movement of member 9i) is limited by a stop 93 which is engageable by the lever 8d.

Thus by swinging the lever 9i) clockwise from its releasably locked position shown in Fig. 3, wherein the contactors 6d are in extended position, the carrier is elevated to retract the contactors and the blades 7d break contact with the contactors 34, 35. Ey swinging the lever counter-clockwise the carrier is moved downwardly to extend the contactors and make connections between the blades and contactors.

The contactors 64 being spring pressed as they are the Vfree ends thereof are adapted to make Contact with energy supply members such as conductors in the form of bus bars or the like.

It will be noted that the contacting portions of the stationary contactors and blades are disposed in the recesses l and Ztl of the insulator i4 while the contacting portions of the blades and movable contactors are disposed in wells 52' of carrier insulator S2 which are surrounded by upstanding barriers 53. Thereby arcing and other .objectionable results are avoided which is inherent in prior art devices.

The plug-in or connector box is adapted for a wide range of uses where it is desired to make connection with energy supply conductors. `For instance the box may be used in connection with duct construction such as shown and described in our pending application.

In such a case it is desired that the box be releasably locked to the duct and that the cover of the box be held in closed position while the box is connected to the duct with the contactors in extended position.

To that end a link i102 is pivoted at 10d to the cover and has an elongated slot lila in its free end. A stud 298 of the carrier is `disposed in the siot itin so that as the contactors are in extended position the cover is held against swinging to open position. As the carrier is elevated to retract the contactors the cover is released for opening.

The cover and box may be provided with locking means well known in switch boxes, junction boxes and the like.

The box may be provided with Various means adapted to cooperate with the lock means of a duct or the like on which it is mounted. In the form of the invention shown such means consists of studs 11d xed to the bottom wall 4 ofthe box which is provided with annular grooves 112.

Movable doors or slide plates of a wall of the duct engage the grooves of the studs which extend through the said wall for locking engagement as appears in the before mentioned application. In locked position on the duct the contactors may be extended to contact energy supply means 116 such as bus bars associated with a duct 118.

The plug-in box may be connected to a panel or to a wall of any apparatus having means for engaging the studs or similar means thereof so that the contactors may be contacted with energy supply conductors associated with the said wall.

The novel operation and arrangement of the circuit closing and opening mechanism will be described in detail with particular reference to Figs. 7, 8 and 9 wherein a single contactor 64 and a single bus bar B are shown. A single stationary contactor 26 is shown.

It will be assumed that the contactor is in engagement with a bus bar represented by B and is urged thereagainst by spring 64'. In this position the cover 1i) is held closed by link 162 as described.

To disengage the contactor 64 from the bus bars B,

member 9i) is swung clockwise breaking the toggle and il initially moving the contactor carrier 52 upwardly from the position of Fig. 7. This causes the carrier to lift the blade 74 out of contact with stationary and movable contactors 26 and 64. In this initial movement contactor 64 is not elevated but its lower end is held in engagement with the bus bar B by spring 64. Thus there is a double break as two points of contact are broken initially while the contactor 64 remains in contact with the bus bar.

Subsequent to the initial movement of the carrier and when the blade 74 is out of contact with contactors 26 and 64 further swinging of member 90 and upward movement of the carrier moves the contactor 64 out of engagement with the bus bar B as in Fig. 9. The operating mechanism is thereafter actuated to the limit of its movement whereupon the link 102 permits the cover 10 to be opened.

The parts are constructed and arranged whereby the carrier may not be moved to extend the contactor while the cover is in its open position.

In extending the contactor for engaging the bus bar the cover 10 must be closed to allow the carrier to be moved. With the cover in closed position the member 90 is swung counterclockwise and before the switch blade 74 is moved sufliciently to make contact with contactors 26 and 64 the end of contactor 64 engages the bus bar B. Thus the contactor 64 being spring pressed yieldingly engages the bus bar for a good iirm contact.

As the carrier approaches the limit of its movement the blade 74 at opposite ends thereof makes simultaneous contact with the contactors 26 and 64.

Thus as the member 90 is swung to extend the contactor the said contactor first makes contact with the bus bar. Thereafter is a double contact of the blade and contactors 26 and 64 to complete a circuit when the mechanism arrives at its locked toggle position. Re versely when the contactor is to be retracted there is at about the time the toggle lock is broken, a double break of the blade and contactors 26 and 64 and thereafter a break between contactor and bus bar B.

Thus the parts and the operation thereof is such as to provide a quick double break for opening `a circuit while the contactor remains in engagement with the bus bar and thereafter a break of the contactor and bus bar. Also there is a quick double contact to close circuit subsequent to contact of the contactor and bus bar and the springs shown and described provide yieldable and rrn contacts of the parts.

While we have illustrated and described the invention as embodied in a specic arrangement, we do not intend to he limited to the details shown since various modications and structural changes may be made without departing in any way from the spirit of the invention.

Without further analysis, the foregoing will so fully reveal the gist of our invention that others can by applying current knowledge readily adapt it for various application without omitting features, that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention, and therefore such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims below.

What it is desired to claim and secure by Letters Patent of the United States is:

l. A plug-in connector box construction comprising in combination a receptacle having an elongated insulator fixed therein provided with spaced recesses, a carrier in the receptacle having an elongated insulator therein prcb vided with spaced wells, movable contactors slidable in the insulator of the carrier each having one end disposed in one of the said wells and each having the other end protruding beyond said wells, stationary contactors carried by said xed insulator having end portions in said recesses, blades extending between and having ends in said recesses and wells for contactinw said stationary and movable contactors, means urging said blades to a corresponding position, operating means wlti'n said receptacle for moving said carrier in normal :h opera tion in opposite directions, and means exterior of the receptable connected to the operating means for actuating said operating means from outside the receptacle.

2. A plug-in connector box of claim l, wherein said movable contactors are moved between extended and retracted positions as said carrier is moved in opposite directions.

3. A plug-in connector box of claim l, wherein said blades are in contact with said stationary and movable contactors in extended position of the latter and out of contact therewith in retracted position thereof.

4. A plug-in connector box of claim l, wherein said recesses and wells of the insulators extend in the direction of movement of said movable contactors.

5. A plug-in connector box of claim l, wherein said movable contactor and carrier are movable in parallel planes.

6. A plug-in connector box of claim l, wherein said blades are guided by one of said insulators for independent movements.

7. A plug-in box for extending and retracting a contactor into and from engagement with a conductor comprising a receptacle, a fixed contactor therein, a `carrier having a movable contactor and being movable between extended and retracted positions, a switch blade for engaging said contactors, said carrier having means to break contact of said blade and at least one of the contactors and thereafter to break contact of said contactor and a conductor as the carrier is moved to retracted position, to make contact of said contactor and a conductor and thereafter to make contact of said blade and contactors as the carrier moves to extended position, said means including operating handle means outside the receptacle.

8. A plug-in box for extending and retracting a oontactor longitudinal into and out of engagement with a conductor comprising a receptacle, a carrier movable between extended and retracted positions having an elongated contactor movable therein for engaging a conductor in extended position of the carrier, a stationary contactor, a movable switch blade for engaging said contactors, and means operable from outside the receptacle arranged to double break said blade and contactors and to double make said blade and contactors prior to and 7 subsequent to retreating and extending said movable contacter by movements of the carrier in opposite directions.

9. A plug-in box for extending and retracting separate contactors into and out of engagement with conductors comprising a receptacle, a plurality of stationary contactors, a carrier movable between extended and retracted posiions having movable contactors, movable switch blades for engaging said contactors, and means operable from outside the box to double break said blades and contacors and thereafter to retract said movable contactors as said carrier is moved from extended to re- '8 tracted position and to extend said contactors into engagement with conductors and thereafter to double make said blades and contactors as said carrier is moved from reracted to extended position.

10. A plug-in box of claim 9, wherein said switch blades are urged in conact engaging direction and said contactors are moved in conductor engaging direction.

References Cited in the iile of this patent UNITED STATES XJATENTS 2,172,633 Wilms Sept. 12, 1939 

